New technique to make biofuel production cheaper

"The synergy between the palladium and the iron is incredible," said lead researcher Yong Wang from the Washington State University in the US.

"When combined, the catalyst is far better than the metals alone in terms of activity, stability and selectivity," Wang added.

One of the biggest challenges in biofuel production is obtaining carbon for fuel while removing oxygen at the same time.

High oxygen content makes biofuel less stable, gooier and less efficient than fossil fuels and not suitable for airplane or diesel fuels.

To improve production it is also important to use as little hydrogen as possible in the reaction.

Iron catalysts have been an inexpensive way to remove oxygen from plant-based materials. But the catalyst can stop working when it interacts with water, which is a necessary part of biofuel production.

They coated the surface of the iron catalysts with very small amounts of palladium, and tested the catalyst using m-cresol, a model for biocrude.

The team found that palladium not only prevents the iron rusting, but attracts hydrogen, necessary to replace the oxygen being removed from the m-cresol. This drives the reaction rate and meant that less hydrogen was needed overall to complete the reaction.

"Of course, in the process, you want to minimise the costs of oxygen removal. In this case, you minimise hydrogen consumption, increase the overall activity and gain high yields of the desired fuel products using much less expensive and more abundant catalyst materials," he concluded.

The study appeared in the journal ACS Catalysis.